[skottie] Fix handling of hidden shapes and layers

TBR=reed@google.com

Bug: skia:8923
Change-Id: I5bd1d4f2ef62ebd95cfae0fe3665960b07ed4ae1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/204082
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

modules/skottie/src/SkottieLayer.cpp

@@ -501,7 +501,10 @@ private:
 
 sk_sp<sksg::RenderNode> AnimationBuilder::attachLayer(const skjson::ObjectValue* jlayer,
                                                       AttachLayerContext* layerCtx) const {
-    if (!jlayer) return nullptr;
+    if (!jlayer || ParseDefault<bool>((*jlayer)["hd"], false)) {
+        // Ignore hidden layers.
+        return nullptr;
+    }
 
     const LayerInfo layer_info = {
         ParseDefault<float>((*jlayer)["ip"], 0.0f),

modules/skottie/src/SkottieShapeLayer.cpp

@@ -563,6 +563,11 @@ sk_sp<sksg::RenderNode> AnimationBuilder::attachShape(const skjson::ArrayValue*
             continue;
         }
 
+        if (ParseDefault<bool>((*shape)["hd"], false)) {
+            // Ignore hidden shapes.
+            continue;
+        }
+
         recs.push_back({ *shape, *info });
 
         switch (info->fShapeType) {